1. Field of the Invention
The present invention relates to collapsible structures, and in particular, to structures having panels that incorporate two or more frame members.
2. Description of the Prior Art
There are presently many collapsible structures that are being provided for use by children and adults. Examples of these collapsible structures are illustrated in the following patents: U.S. Pat. No. 5,560,385 (Zheng), U.S. Pat. No. 5,778,915 (Zheng), U.S. Pat. No. 4,815,784 (Zheng), U.S. Pat. No. 5,452,934 (Zheng), U.S. Pat. No. 5,941,265 (Zheng), U.S. Pat. No. 4,858,634 (McLeese) and U.S. Pat. No. 4,825,592 (Norman), among others. These collapsible structures are supported by one or more frame members that can be twisted and folded to reduce the overall size of the structure. Each frame member typically supports and defines one or more collapsible panels. These collapsible structures can be used in a wide variety of applications, such as containers, tents, play structures, executive toys, shelters, sports structures, and others. As a result, collapsible structures have become very popular.
Even though these collapsible structures exhibit surprising versatility in their utility and wide-ranging applications, the consumer is always demanding greater enhancements, better and more features, added convenience, and other related factors. Related to the pursuit of added enhancements and features, one potential drawback associated with these structures is that only one frame member is used to support each collapsible panel. A single frame member can adequately support a smaller panel, but if a larger panel is needed for the desired application, the use of a single frame member may not provide sufficient structural support for the panel, so that the stability of the resulting structure may be structurally weak. For example, large tents, game and sport centers, and other related structures often require large panels to define the resulting structures. Thus, the use of a single frame member to support a panel limits the sizes and shapes in which the resulting structure can be provided.
The use of a single frame member to support a panel also imposes other limitations on the resulting panel or structure. For example, the frame member for most of these collapsible structures typically defines the periphery of its associated panel, so that the periphery of these panels would be relatively rigid and stable. However, the other portions (e.g., portions covered by the fabric associated with the frame member to form the panel) would have less support, which would make it more difficult to attach other panels and objects to such portions.
Thus, there remains a need to provide collapsible panels that overcome the drawbacks mentioned above, and which can be used for a wide variety of structures and applications.